Refrigeration apparatus for air conditioned passenger vehicles



M. E. HANSON Filed NOV. 15, 1941 um \QEFEQSQE T I AN mm mm. \m

kOWmQQQZDU Feb. 16, 1943.

REFRIGERATION APPARATUS FOR AIR CONDITIONED PASSENGER VEHICLES by W J%Patented Feb. 16, 1943 DB'dl U uum REFRIGERATION APPARATUS FOR AIR CON-DITIONED PASSENGER VEHICLES Milton E. Hanson, Haddonficld, N. J.,assignor to B. F. Sturtevant Company, Boston, Mass.

Application November 13, 1941, Serial No. 418,910

2 Claims.

This invention relates to refrigeration apparatus for air conditioning,and relates more particularly to refrigeration apparatus for airconditioned passenger vehicles, which apparatus is driven by internalcombustion engines.

Due to the loads of the axle driven refrigeration equipment of airconditioned, railway passenger cars on the locomotive, it is desirableto energize the refrigeration equipment by auxiliary internal combustionengines utilizing fuels such, for example, as propane. This inventionprovides refrigeration apparatus so energized and provides controls forthe efflcient operation of the equipment.

A feature of the invention resides in continu-. ously operating theinternal combustion engine at idling speed during periods of reducedload when refrigeration is not required and disconnecting the compressortherefrom as by a centrifugal clutch.

Other features of the invention reside in starting and stopping theengine and operating it at different speeds, under thermostat control totake care of all operating conditions.

Objects of the invention are to improve the performance of and to reducethe maintenance cost of refrigeration apparatus driven by an internalcombustion engine.

The invention will now be described with reference to the drawing, ofwhich:

Fig. 1 is a diagrammatic view of a railway passenger car conditioningsystem embodying this invention, and

Fig. 2 is an internal view of one form of a centrifugal clutch which maybe used for driving the compressor of Fig. 1 by the engine thereof.

The blower 5 of Fig. 1, draws outdoor air through the inlet 6, andrecirculated air from the passenger space through the inlet I, passes itthrough the conditioner 8 and then through the usual overhead duct 4,into the passenger space.

The conditioner 8 includes a refrigerant evaporator for cooling the air,which evaporator comprises the inlet header tubes 9 connected to theexpansion valve and distributor I3, and the inlet header tubes llconnected to the expansion valve l2. The evaporator also comprises thesuction header tubes 13 connected by the suction line H, which includesthe valve I5, and by the suction line I! to the suction side of thecompressor ll. The evaporator also comprises the suction header tubes 13connected by the suction line I! to the suction line I3.

The compressor I! supplies refrigerant through the supply line 23, thecondenser 2|, the valve 22, the receiver 23, the drier 24, the valve 25,the supercooler 23, the pressurestat 21 and supply line 23 to theexpansion valve distributors l0 and I2.

All of the evaporator tubes are enclosed by the usual spaced, vertical,sheet fins 59. By having alternate suction header tubes connected to thedifferent suction lines It and I3 and by closing the valve I! in theline H, one-half of the evaporator may be rendered inactive, yet theactive tubes will extend across the air stream and through the use ofthe common interconnectin fins 23 will act to cool and dehumidify theair in the areas of the inactive tubes thus preventing the reevaporationof moisture into the air stream, previously condensed when the inactivetubes were active.

The compressor I1 is driven through the centrifugal clutch 23 by theinternal combustion engine 30. The fan 3| on the engine shaft 32 movesair through the condenser 21 to cool same.

The centrifugal clutch 29 includes the inner clutch member 33 connectedto the engine shaft, the outer clutch members 34 which are pivoted at 35and connected to the governor type balls 36. At engine speeds below 600R. P. M., the balls 35 assume the position illustrated by Fig. 2 withthe outer clutch members 34 out of contact with the inner clutch member33. At speeds above 600 R. P. M., the balls 36 move outwardly throughcentrifugal force and move the outer clutch members 34 in tight contactwith the inner clutch member 33. The outer clutch members are connectedat the pivots 35 to the shell of the clutch 29 and through same to theshaft 31 of the compressor so that the compressor is connected to theengine at engine speeds above 600 R. P. M. and is disconnected from theengine at lower engine speeds.

The three thermostats 33, 33 and 40 are mounted above the inlet 1 in thepath of the recirculated air from the passenger space. The thermostat 33is an electric thermostat and closes its contacts at say 72 F. to closean electric circuit including the relay 4|, the ignition equipment 43,and the starter motor 42, for starting the engine 33. The starterequipment may be of the well known Startex type in general use on thehigher prices automobiles for maintaining the engine in operation solong as the thermostat 33 has its contacts closed.

The thermostat 33 is of the modulating bellows type and is connected bythe tube 44 to the bellows actuating element 45 which adjusts thethrottle valve of the carburetor 46 for varying the speed of the engine30. At say 76 F., the engine speed may be maintained at about 1200 R. P.M. At say 82 F., the engine speed may be maintained at about 1600 R. P.M. which may be full speed. The volume of refrigerant delivered by thecompressor varies with engine speed so that increased refrigeration isprovided when required.

The thermostat 40 which is electric, closes its contacts at below say 76F., causing energization of the solenoid 41 causing the valve IE toclose and one section of the evaporator to become inactive thusdecreasing the evaporator surface for reduced loads.

The pressurestat 2! acts when the head pressure in the line 28 risesabove 180 pounds, to close the electric circuit of the motor 48 causingit to operate the fan 49 for moving air through the super-cooler 26, andto operate the pump 50 causing it to draw water from the tank 5| and tosupply it through the pipe 52 to the spray nozzle 53 which sprays waterupon the tubes of the super-cooler for the evaporative cooling thereof.

While one embodiment of the invention has been described for the purposeof illustration, it should be understood that the invention is notlimited to the exact apparatus and arrangement of apparatus illustrated,as modifications thereof may be suggested by those skilled in the artwithout departure from the essence of the invention.

What is claimed is:

l. Refrigeration apparatus for air cooling comprising means including anevaporator forming an air cooler, means including a compressor forsupplying refrigeration to said evaporator, an internal combustionengine for driving said compressor, mea means responsive to tempegatumc'served for star g said engine when the space temperature is above apredetermined point, for reducing the effective surface of saidevaporator and for reducing the speed of said engine when the spacetemperature has fallen below another predetermined point, amt-13m'r'emicing the speed of said engine toggling speed when the space tem'-perature has a en to a predetermined point belowsaid Ia'st" mentionedpredetermined point, and a CEI1I1IE81 clutch between said compressor andengine or sconnecting sa compressor from said engine at idling speed.

2. Refrigm apparatus for air cooling comprising means including anevaporator forming an air cooler, means including a compressor forsupplying refrigeration to said evaporator, an internal combustionengine for driving said compressor, means including means responsive totemperature changes in the space served for reducing the effectivesurface of said evaporator and for reducing the speed of said enginewhen the space temperature has fallen to a predetermined point, and forreducing the speed of said engine to idling speed when the spacetemperature has fallen to a predetermined point below said lastmentioned predetermined point, and a centrifugal clutch between saidcompressor and engine for disconnecting said compressor from said engineat idling speed.

MILTON E. HANSON.

anew-yr,

